Software design is about a sequence of steps taken to achieve a goal. Designers must plan their approach to carrying out these steps. In studying designers at work, the authors observed breadth- versus depth-first approaches to design-space exploration and problem- versus solution-driven approaches during the actual design. Which approaches and when to use them are important to effective design. The authors suggest four archetypical strategies that designers can choose under different circumstances, thus making design strategy one of the early design decisions.